1. Field of the Invention
The present invention pertains to a method and apparatus for recovering crude oil and similar oily substances from oil soaked beach sands and other earth materials by a combined mechanical and hydraulic agitation process.
2. Background
It has been observed that heavy concentrations of hydrocarbon materials such as crude oils and refined oily wastes associated with oil spills and discharges into collection pits results in substantial penetration or percolation of the oil into sandy or other granular soil surfaces. In attempting to recover spilled oil from marine oil spills, it has been discovered that along shore lines having relatively coarse bottom sediments, crude oil washed onto the shore will penetrate into the sediments forming the shoreline and the sea bottom in shallow waters. The penetration of oil into a relatively wide area is aggravated in tidal waters if the oil cannot be quickly recovered by conventional surface recovery techniques. This penetration of oil into the earth's surface not only reduces the amount of oil recovered, and may be environmentally damaging, but prevents the complete removal of the oil after a spill or when the eradication of dumping pits or holding ponds for oily wastes and the like is required. Moreover, the complete removal of the oil soaked sediments or sand for processing at a remote site to remove the entrapped oil is very impractical or even impossible if large quantities of oil are washed ashore or soak into the sediments.